Optical fiber and method of producing

Abstract

A starting material for producing optical fibers contains metal halides. The refractive index of the optical fiber formed from the starting material is predeterminable by adjusting a partial pressure ratio of a halogen-containing gas mixture. The starting material is produced by mixing halogenated gases into a gas mixture with the desired partial pressure ratio, causing a chemical reaction at a first temperature of the gas mixture with at least metal to form a reaction product, the first temperature being higher than the melting temperature of the reaction product and cooling the reaction product to a second temperature that is below the melting temperature.

What is claimed is:  
     
         1 . A process for manufacturing a starting material for an optical fiber, the starting material containing metal hialides and having a predetermined refractive index, the process comprising the steps of: 
 mixing halogen-containing gases to form a gas mixture with a partial pressure ratio, upon which the predetermined refractive index depends;    causing the gas mixture to react chemically at a first temperature with a metal to form a reaction product having a melting point, such that the first temperture is at least the melting point; and    cooling the reaction product to a second temperture below the melting point.    
     
     
         2 . The process of  claim 1 , wherein the reaction product is a solid solution of metal halides.  
     
     
         3 . The process of  claim 1 , wherein the metal is selected from a group consisting of the alkali metals, thallium and silver.  
     
     
         4 . The process of  claim 2 , wherein the metal is selected from a group consisting of the alkali metals, thallium and silver.  
     
     
         5 . The process of  claim 4 , wherein the solid solution contains silver bromide, silver chloride or a combination of silver bromide and silver chloride.  
     
     
         6 . The process of  claim 3 , wherein the solid solution contains silver bromide, silver chloride or a combination of silver bromide and silver chloride.  
     
     
         7 . The process of  claim 5 , wherein the halogen-containing gas contains bromine.  
     
     
         8 . The process of  claim 6 , wherein the halogen-containing gas contains bromine.  
     
     
         9 . The process of  claim 1 , wherein the halogen-containing gas contains bromine.  
     
     
         10 . The process of  claim 7 , wherein the halogen-containing gas contains chlorine.  
     
     
         11 . The process of  claim 8 , wherein the halogen-containing gas contains chlorine.  
     
     
         12 . The process of  claim 9 , wherein the halogen-containing gas contains chlorine.  
     
     
         13 . The process of  claim 1 , wherein the halogen-containing gas contains chlorine.  
     
     
         14 . The process of  claim 10 , wherein the gas mixture partial pressure ratio is set so that the solid solution contains bromine and chlorine in a particle number ratio of 3 to 1.  
     
     
         15 . The process of  claim 14 , further comprising the step of: 
 purifying the reaction product before the cooling step below the melting point thereof.    
     
     
         16 . The process of  claim 11 , further comprising the step of: 
 purifying the reaction product before the cooling step below the melting point thereof.    
     
     
         17 . The process of  claim 12 , further comprising the step of: 
 purifying the reaction product before the cooling step below the melting point thereof.    
     
     
         18 . The process of  claim 13 , further comprising the step of: 
 purifying the reaction product before the cooling step below the melting point thereof.    
     
     
         19 . The process of  claim 15 , wherein the cooling step is achieved while feeding the reaction product in a furnace along a temperature gradient in a furnace from the first temperature to the second temperature.  
     
     
         20 . The process of  claim 16 , wherein the cooling step is achieved while feeding the reaction product in a furnace along a temperature gradient in a furnace from the first temperature to the second temperature.  
     
     
         21 . The process of  claim 17 , wherein the cooling step is achieved while feeding the reaction product in a furnace along a temperature gradient in a furnace from the first temperature to the second temperature.  
     
     
         22 . The process of  claim 18 , wherein the cooling step is achieved while feeding the reaction product in a furnace along a temperature gradient in a furnace from the first temperature to the second temperature.  
     
     
         23 . A process for manufacturing a blank for optical fibers, comprising the steps of: 
 guiding at least one molten starting material through at least two tubes having different diameters, wherein a first of the at least two tubes surrounds a second of the at least two tubes;    continually bringing together the staring material near a discharge opening of the seond tube in a diffusion zone; and    converting the starting material through the diffusion zone in a solid phase.    
     
     
         24 . The process of  claim 23 , wherein the guiding step comprises: 
 guiding at least two molten starting materials which differ in the concentration of the constituents thereof.    
     
     
         25 . The process of  claim 24 , wherein the starting materials pass through a profile of diminishing temperature in the longitudinal direction of the tubes until being united in the diffusion zone, so that the temperature of the starting materials reaches the melting temperature thereof in the area of the discharge opening.  
     
     
         26 . The process of  claim 23 , wherein the starting materials pass through a profile of diminishing temperature in the longitudinal direction of the tubes until being united in the diffusion zone, so that the temperature of the starting materials reaches the melting temperature thereof in the area of the discharge opening.  
     
     
         27 . The process of  claim 25 , wherein the first tube is moved relative to the second tube so that the molten starting material is always converted at about the same distance from the discharge opening of the second tube into the first tube.  
     
     
         28 . The process of  claim 26 , wherein the first tube is moved relative to the second tube so that the molten starting material is always converted at about the same distance from the discharge opening of the second tube into the first tube.  
     
     
         29 . An apparatus for a process for manufacturing a blank for optical fibers, comprising: 
 at least two tubes;    a first of the at least two tubes surrounding a second tube of the at least two tubes in at least a front surface of the second tube, and    a heating apparatus for producing a temperature profile in the at least two tubes, the profile changeable in a longitudinal direction of the first tube,    wherein the front surface has a surface section, a perpendicular thereto forming an acute angle with a longitudinal axis of the second tube.    
     
     
         30 . The apparatus of  claim 29 , wherein the front surface runs parallel to a phase boundary surface between a liquid and a solid phase that forms at a distance before the tube discharge opening while operating the apparatus.  
     
     
         31 . The apparatus of  claim 30 , wherein the front surface is curved.  
     
     
         32 . The apparatus of  claim 29 , wherein the front surface is curved.  
     
     
         33 . The apparatus of  claim 31 , wherein the front surface is convexly curved.  
     
     
         34 . The apparatus of  claim 32 , wherein the front surface is convexly curved.  
     
     
         35 . The apparatus of  claim 33 , wherein the first tube is mounted to be longitudinally displaceable.  
     
     
         36 . The apparatus of  claim 34 , wherein the first tube is mounted to be longitudinally displaceable.  
     
     
         37 . The apparatus of  claim 35 , wherein at least two second tubes run concentrically to the first tube within the first tube, the second of the second tubes runnig at a distance to the longitudinal axis of the first and the first of the second tubes.  
     
     
         38 . The apparatus of  claim 36 , wherein at least two second tubes run concentrically to the first tube within the first tube, the second of the second tubes runnig at a distance to the longitudinal axis of the first and the first of the second tubes.  
     
     
         39 . A process for manufacturing an optical fiber from a blank of starting material, the starting material extruded through a vibrated nozzle.  
     
     
         40 . The process of  claim 39 , wherein the virbation is in an ultrasonic range.  
     
     
         41 . A device for extruding an optical fiber from a blank of starting material, comprising: 
 a ram that can be displaced longitudinally, and    a nozzle, and    a vibrator, coupled to the nozzle.    
     
     
         42 . The extrusion device of  claim 41 , wherein the vibrator comprises a piezoelectric crystal.  
     
     
         43 . The extrusion device of  claim 42 , wherein the blank of a first cross-sectional shape and the nozzle has a second cross-sectional shape that differs from the first cross sectional shape.  
     
     
         44 . The extrusion device of  claim 43 , wherein the blank has a circular cross sectional shape and the nozzle has a square cross sectional shape.  
     
     
         45 . An optical fiber for transmitting radiation, comprising: 
 a fiber end characterized by a reduced reflectivity microstructure.    
     
     
         46 . The optical fiber of  claim 45 , wherein the microstructure is impressed on the fiber material.  
     
     
         47 . The optical fiber of  claim 46 , wherein the microstructurescatters at least a portion of the radiation emerging therefrom.  
     
     
         48 . The optical fiber of  claim 45 , wherein the microstructure scatters at least a portion of the radiation emerging therefrom.  
     
     
         49 . The optical fiber of  claim 48 , wherein an element having the microstructure is affixed to the end of the fiber.  
     
     
         50 . The optical fiber of  claim 45 , wherein an element having the microstructure is affixed to the end of the fiber.  
     
     
         51 . The optical fiber of  claim 50 , wherein the element is a radiation filter that is transparent to certain wavelengths of the radiation.  
     
     
         52 . The optical fiber of  claim 51 , wherein the element is designed to be chemically resistant to substances that are present in its environment.  
     
     
         53 . The optical fiber of  claim 52 , wherein the element is an artificial diamond.  
     
     
         54 . The optical fiber of  claim 49 , wherein the element is an artificial diamond.  
     
     
         55 . An optical fiber, comprising: 
 a plurality of light-conducting channels,    the channels running internal to the fiber in a longitudinal direction,    every channel capable of conducting light through the fiber independent of the other channels.    
     
     
         56 . The optical fiber of  claim 55 , wherein the channels are arranged in a matrix with respect a cross-section of the fiber.  
     
     
         57 . The optical fiber of  claim 56 , wherein the channels are arranged in a rectangular matrix.  
     
     
         58 . The optical fiber of  claim 57 , wherein an outside cross-section of the fiber is angular.  
     
     
         59 . The optical fiber of  claim 58 , wherein the outside cross section is rectangular.  
     
     
         60 . The optical fiber of  claim 58 , wherein the outside cross section is square.  
     
     
         61 . A fiber bundle, comprising: 
 a plurality of optical fibers, each said fiber having an angular outside cross-sections;    each said fiber comprising: 
 a plurality of light-conducting channels,  
 the channels running internal to the fiber in a longitudinal direction,  
 every channel capable of conducting light through the fiber independent of the other channels.  
   
     
     
         62 . An optical fiber, wherein the fiber comprises at least one light-conducting channel with a rectangular, longitudinally-extending cross-section.